Caesar cipherCaesar cipher, is one of the simplest and most widely known encryption techniques.
The transformation can be represented by aligning two alphabets,
the cipher alphabet is the plain alphabet rotated left or right by some number of positions.
When encrypting, a person looks up each letter of the message in the 'plain'
line and writes down the corresponding letter in the 'cipher' line. Deciphering is done in reverse.
The encryption can also be represented using modular arithmetic
by first transforming the letters into numbers, according to the scheme, A = 0, B = 1,..., Z = 25.
Encryption of a letter x by a shift n can be described mathematically as
Plaintext: flandrin

cipher variations:

gmboesjo

hncpftkp

iodqgulq

jperhvmr

kqfsiwns

lrgtjxot

mshukypu

ntivlzqv

oujwmarw

pvkxnbsx

qwlyocty

rxmzpduz

synaqeva

tzobrfwb

uapcsgxc

vbqdthyd

wcreuize

xdsfvjaf

yetgwkbg

zfuhxlch

agviymdi

bhwjznej

cixkaofk

djylbpgl

ekzmcqhm

Decryption is performed similarly,
(There are different definitions for the modulo operation.
In the above, the result is in the range 0...25. I.e., if x+n or x-n are not in the range 0...25,
we have to subtract or add 26.)
Read more ...Atbash CipherAtbash is an ancient encryption system created in the Middle East.
It was originally used in the Hebrew language.
The Atbash cipher is a simple substitution cipher that relies on
transposing all the letters in the alphabet such that the resulting alphabet is backwards.
The first letter is replaced with the last letter, the second with the second-last, and so on.
An example plaintext to ciphertext using Atbash:

Baconian CipherTo encode a message, each letter of the plaintext is replaced by a group of five of the letters 'A' or 'B'.
This replacement is done according to the alphabet of the Baconian cipher, shown below.

Affine CipherIn the affine cipher the letters of an alphabet of size m are first mapped to the integers
in the range 0..m - 1. It then uses modular arithmetic to transform the integer that each plaintext
letter corresponds to into another integer that correspond to a ciphertext letter.
The encryption function for a single letter is
where modulus m is the size of the alphabet and a and b are the key of the cipher.
The value a must be chosen such that a and m are coprime.Considering the specific case of encrypting messages in English (i.e. m = 26),
there are a total of 286 non-trivial affine ciphers, not counting the 26 trivial Caesar ciphers.
This number comes from the fact there are 12 numbers that are coprime with 26 that are less than 26
(these are the possible values of a). Each value of a can have 26 different addition shifts (the b value)
; therefore, there are 12*26 or 312 possible keys.Plaintext: flandrin

cipher variations:

gmboesjo

qibokazo

aeboqipo

kabowqfo

uwbocyvo

esboiglo

ykbouwro

igboaeho

scbogmxo

cybomuno

muboscdo

wqboykto

hncpftkp

rjcplbap

bfcprjqp

lbcpxrgp

vxcpdzwp

ftcpjhmp

zlcpvxsp

jhcpbfip

tdcphnyp

dzcpnvop

nvcptdep

xrcpzlup

iodqgulq

skdqmcbq

cgdqskrq

mcdqyshq

wydqeaxq

gudqkinq

amdqwytq

kidqcgjq

uedqiozq

eadqowpq

owdquefq

ysdqamvq

jperhvmr

tlerndcr

dhertlsr

nderztir

xzerfbyr

hverljor

bnerxzur

ljerdhkr

vferjpar

fberpxqr

pxervfgr

zterbnwr

kqfsiwns

umfsoeds

eifsumts

oefsaujs

yafsgczs

iwfsmkps

cofsyavs

mkfseils

wgfskqbs

gcfsqyrs

qyfswghs

aufscoxs

lrgtjxot

vngtpfet

fjgtvnut

pfgtbvkt

zbgthdat

jxgtnlqt

dpgtzbwt

nlgtfjmt

xhgtlrct

hdgtrzst

rzgtxhit

bvgtdpyt

mshukypu

wohuqgfu

gkhuwovu

qghucwlu

achuiebu

kyhuomru

eqhuacxu

omhugknu

yihumsdu

iehusatu

sahuyiju

cwhueqzu

ntivlzqv

xpivrhgv

hlivxpwv

rhivdxmv

bdivjfcv

lzivpnsv

frivbdyv

pnivhlov

zjivntev

jfivtbuv

tbivzjkv

dxivfrav

oujwmarw

yqjwsihw

imjwyqxw

sijweynw

cejwkgdw

majwqotw

gsjwcezw

qojwimpw

akjwoufw

kgjwucvw

ucjwaklw

eyjwgsbw

pvkxnbsx

zrkxtjix

jnkxzryx

tjkxfzox

dfkxlhex

nbkxrpux

htkxdfax

rpkxjnqx

blkxpvgx

lhkxvdwx

vdkxblmx

fzkxhtcx

qwlyocty

aslyukjy

kolyaszy

uklygapy

eglymify

oclysqvy

iulyegby

sqlykory

cmlyqwhy

milywexy

welycmny

galyiudy

rxmzpduz

btmzvlkz

lpmzbtaz

vlmzhbqz

fhmznjgz

pdmztrwz

jvmzfhcz

trmzlpsz

dnmzrxiz

njmzxfyz

xfmzdnoz

hbmzjvez

synaqeva

cunawmla

mqnacuba

wmnaicra

ginaokha

qenausxa

kwnagida

usnamqta

eonasyja

oknaygza

ygnaeopa

icnakwfa

tzobrfwb

dvobxnmb

nrobdvcb

xnobjdsb

hjobplib

rfobvtyb

lxobhjeb

vtobnrub

fpobtzkb

plobzhab

zhobfpqb

jdoblxgb

uapcsgxc

ewpcyonc

ospcewdc

yopcketc

ikpcqmjc

sgpcwuzc

mypcikfc

wupcosvc

gqpcualc

qmpcaibc

aipcgqrc

kepcmyhc

vbqdthyd

fxqdzpod

ptqdfxed

zpqdlfud

jlqdrnkd

thqdxvad

nzqdjlgd

xvqdptwd

hrqdvbmd

rnqdbjcd

bjqdhrsd

lfqdnzid

wcreuize

gyreaqpe

quregyfe

aqremgve

kmresole

uireywbe

oarekmhe

ywrequxe

isrewcne

soreckde

ckreiste

mgreoaje

xdsfvjaf

hzsfbrqf

rvsfhzgf

brsfnhwf

lnsftpmf

vjsfzxcf

pbsflnif

zxsfrvyf

jtsfxdof

tpsfdlef

dlsfjtuf

nhsfpbkf

yetgwkbg

iatgcsrg

swtgiahg

cstgoixg

motguqng

wktgaydg

qctgmojg

aytgswzg

kutgyepg

uqtgemfg

emtgkuvg

oitgqclg

zfuhxlch

jbuhdtsh

txuhjbih

dtuhpjyh

npuhvroh

xluhbzeh

rduhnpkh

bzuhtxah

lvuhzfqh

vruhfngh

fnuhlvwh

pjuhrdmh

agviymdi

kcvieuti

uyvikcji

euviqkzi

oqviwspi

ymvicafi

sevioqli

caviuybi

mwviagri

wsvigohi

govimwxi

qkviseni

bhwjznej

ldwjfvuj

vzwjldkj

fvwjrlaj

prwjxtqj

znwjdbgj

tfwjprmj

dbwjvzcj

nxwjbhsj

xtwjhpij

hpwjnxyj

rlwjtfoj

cixkaofk

mexkgwvk

waxkmelk

gwxksmbk

qsxkyurk

aoxkechk

ugxkqsnk

ecxkwadk

oyxkcitk

yuxkiqjk

iqxkoyzk

smxkugpk

djylbpgl

nfylhxwl

xbylnfml

hxyltncl

rtylzvsl

bpylfdil

vhylrtol

fdylxbel

pzyldjul

zvyljrkl

jrylpzal

tnylvhql

ekzmcqhm

ogzmiyxm

yczmognm

iyzmuodm

suzmawtm

cqzmgejm

wizmsupm

gezmycfm

qazmekvm

awzmkslm

kszmqabm

uozmwirm

flandrin

phanjzyn

zdanphon

jzanvpen

tvanbxun

dranhfkn

xjantvqn

hfanzdgn

rbanflwn

bxanltmn

ltanrbcn

vpanxjsn

The decryption function iswhere a - 1 is the modular multiplicative inverse of a modulo m. I.e., it satisfies the equationThe multiplicative inverse of a only exists if a and m are coprime.
Hence without the restriction on a decryption might not be possible.
It can be shown as follows that decryption function is the inverse of the encryption function,Read more ...

ROT13 CipherApplying ROT13 to a piece of text merely requires examining its alphabetic
characters and replacing each one by the letter 13 places further along in the alphabet,
wrapping back to the beginning if necessary. A becomes N, B becomes O, and so on up to M,
which becomes Z, then the sequence continues at the beginning of the alphabet: N becomes A,
O becomes B, and so on to Z, which becomes M. Only those letters which occur in the English
alphabet are affected; numbers, symbols, whitespace, and all other characters are left unchanged.
Because there are 26 letters in the English alphabet and 26 = 2 * 13, the ROT13 function is its own inverse:

Polybius SquareA Polybius Square is a table that allows someone to translate letters into numbers.
To give a small level of encryption, this table can be randomized and shared with the recipient.
In order to fit the 26 letters of the alphabet into the 25 spots created by the table, the letters
i and j are usually combined.

1

2

3

4

5

1

A

B

C

D

E

2

F

G

H

I/J

K

3

L

M

N

O

P

4

Q

R

S

T

U

5

V

W

X

Y

Z

Basic Form:

Plain:

flandrin

Cipher:

1213113341244233

Extended Methods:Method #1

Plaintext: flandrin

method variations:

lqfsiwos

qvlxobtx

vaqctgyc

afvhymdh

Method #2Bifid cipherThe message is converted to its coordinates in the usual manner, but they are written vertically beneath:

f l a n d r i n
1 1 1 3 4 2 4 3
2 3 1 3 1 4 2 3

They are then read out in rows:
1113424323131423Then divided up into pairs again, and the pairs turned back into letters using the square:

Permutation CipherIn classical cryptography, a permutation cipher is a transposition cipher in which the key is a permutation.
To apply a cipher, a random permutation of size E is generated (the larger the value of E the more secure the cipher).
The plaintext is then broken into segments of size E and the letters within that segment are permuted according to
this key.
In theory, any transposition cipher can be viewed as a permutation cipher where E is equal to the
length of the plaintext; this is too cumbersome a generalisation to use in actual practice, however.
The idea behind a permutation cipher is to keep the plaintext characters unchanged,
butalter their positions by rearrangement using a permutation
This cipher is defined as:Let m be a positive integer, and K consist of all permutations of {1,...,m}For a key (permutation) , define:
The encryption function The decryption function A small example, assuming m = 6, and the key is the permutation
:The first row is the value of i,
and the second row is the corresponding value of (i)The inverse permutation, is constructed by interchanging the two rows,
andrearranging the columns so that the first row is in increasing order, Therefore, is:
Total variation formula: e = 2,718281828 , n - plaintext length